1. Field of the Invention
This invention relates to a percussion tool for comminuting materials, in particular wood waste materials, having a beater head and a shank, wherein a cutting insert with an upper cutting edge extending transversely with respect to the cutting direction is fastened on the beater head.
2. Discussion of Related Art
The shanks of exchangeable beaters for the comminution of wood or wood waste can be inserted into a receiver of a holder and fastened on the holder. The holder is pivotably seated on a rotatory body. The rotatory body is installed in a reception housing, in which the material to be comminuted is also stored.
With the rotary body turning, the percussion tools beat and divide the material to be comminuted. As fine of a defibration as possible is advantageous, because it accelerates subsequent composting. When encountering hard objects, such as stones, in the cut material to be comminuted, the holder can pivot out and yield in order to avoid impermissibly large stresses. However, damage of the cutting insert can occur because of the large stresses. A known cutting insert is divided into cutting elements or individual teeth, so that the loss of a single cutting element does not result in the loss of the entire tool.
A percussion tool is taught by German Patent Reference DE 102 23 887 A1. A cutting head is described therein, which has a main cutting element supported by a base element. For improving the cutting output, the cutting head has at least one additional cutting element extending transversely with respect to the cutting direction on both sides of the main cutting element. The embodiment described in this publication provides that the lateral cutting elements are placed at a spatial distance from the main cutting element.
One disadvantage of this arrangement is that in connection with the tool insert for comminuting green material, erosions can occur on the cutting head in the area of the holder of the hard alloy cutting elements. Erosion can also damage the front facing the material to be communicated in a disadvantageous manner during extended operations. Therefore the known cutting body is customarily used for splitting aged wood.
A cutting body with an extended service life is described in German Patent Reference G 93 05 835.7. In this case, the cutting body is substantially embodied as a cast part with a cutting edge extending parallel with respect to the circumferential axis, wherein the cutting edge has several side-by-side arranged element sectors made of a hard alloy as wear elements.
It is thus disadvantageous if the cutting elements, on their sides facing away from the material to be cut, are partially not supported by the cutting head and are thus prone to break, as well as to become separated.